Mount

Abstract

A mount for connecting two relative-vibratable objects has two resilient elements and a signal actuated clutch for connecting the objects. The clutch is in parallel with one of the resilient elements and in parallel with the other. A sensor senses the vibrations applied across the mount and actuates the clutch in response thereto to change the transfer function of the mount. Appropriately controlling the engagement/disengagement actuation of the clutch in this way makes it possible to avoid the resonant frequencies of the mount and thus both isolate and damp the vibrations as desired without structural changes to the mount.

What is claimed is: 
     
       1. A mount for connecting two relatively-vibratable objects, comprising: two resilient elements and a signal-actuated clutch for connecting two relatively-vibratable objects in the direction of the relative vibrations thereof, the clutch being in parallel with one of the resilient elements and in series with the other; and   sensor means responsive to the relative vibrations of the objects at least at a resonant frequency of the mount with a signal for actuating the clutch, thereby to change the transfer function of the mount so as to avoid the resonant frequency of the mount.   
     
     
       2. The mount of claim 1, wherein the clutch and one of the resilient elements are connected in series as a unit for connecting the objects and the other resilient element is in parallel with the unit for connecting the objects. 
     
     
       3. The mount of claim 1, and further comprising intermediate means connected to the clutch and one of the resilient elements for connecting these to one of the objects in parallel and connected to the other resilient element for connecting it to the other of the objects. 
     
     
       4. An engine mount for a vehicle, comprising: a pedestal for connection to the engine;   a mounting fixture for connection to the vehicle;   a first resilient element connected between the pedestal and mounting fixture;   a second resilient element and signal-actuated clutch connected in series between the pedestal and mounting fixture; and   sensor means responsive to relative vibration between the pedestal and mounting fixture with a corresponding signal for engaging the clutch when the signal exceeds a threshold value.   
     
     
       5. The engine mount of claim 4, wherein the maximum holding force of the clutch engagement is less than the maximum spring force of the first resilient element. 
     
     
       6. The engine mount of claim 4, wherein the spring force of the first resilient element is smaller than the spring force of the second resilient element. 
     
     
       7. The engine mount of claim 6, wherein the ratio of the spring force of the second resilient element to that of the first is from about 2 to about 4. 
     
     
       8. The engine mount of claim 4, wherein the clutch comprises interfitting plates, alternate ones of the plates forming the opposite ends of the clutch in the direction of the vibration and magnetic means for variably holding the plates together. 
     
     
       9. The engine mount of claim 8, wherein the interfitting plates have complementary chevron shapes in the direction of the vibration. 
     
     
       10. The engine mount of claim 9, wherein the angle of the chevron shape of the plates is from about 5° to about 15°. 
     
     
       11. The engine mount of claim 4, wherein the clutch comprises a friction column connected to one end of the clutch and magnetically-actuatable clamping surface means connected to the other end of the clutch for clamping about the friction column. 
     
     
       12. The engine mount of claim 11, wherein the clamping surface means comprises magnetically-actuatable means for producing a fluid pressure and means responsive to the fluid pressure for clamping about the friction column. 
     
     
       13. An engine mount for a vehicle, comprising: first and second resilient elements and a signal-actuated clutch;   a pedestal for connection to the engine;   a mounting fixture for connection to the vehicle;   intermediate means between the pedestal and mounting fixture for connecting the first resilient element and the clutch in parallel therefrom to one of the pedestal and mounting fixture and for connecting tne second resilient element therefrom to the other of the pedestal and mounting fixture; and   sensor means responsive to relative vibration between the pedestal and mounting fixture with a corresponding signal for engaging the clutch when the signal exceeds a threshold value.   
     
     
       14. The engine mount of claim 13, wherein the maximum holding force of the clutch engagement is less than the maximum spring force of the first resilient element. 
     
     
       15. The engine mount of claim 13, wherein the spring force of the first resilient element is smaller than the spring force of the second resilient element. 
     
     
       16. The engine mount of claim 15, wherein the ratio of the spring force of the second resilient element to that of the first is from about 2 to about 4. 
     
     
       17. The engine mount of claim 13, wherein the clutch comprises interfitting plates forming, alternately, opposite ends of the clutch in the direction of the vibration and magnetic means for variably holding the plates together. 
     
     
       18. The engine mount of claim 17, wherein the interfitting plates have complementary chevron shapes in the direction of the vibration. 
     
     
       19. The engine mount of claim 18, wherein the angle of the chevron shape of the plates is from about 5° to about 15°. 
     
     
       20. The engine mount of claim 13, wherein the clutch comprises a friction column connected to one end of the clutch and magnetically-actuatable clamping surface means connected to the other end of the clutch for clamping about the friction column. 
     
     
       21. The engine mount of claim 20, wherein the clamping surface means comprises magnetically-actuatable means for producing a fluid pressure and means responsive to the fluid pressure for clamping about the friction column.